Subaru 2002 IMPREZA Service Manual page 1695

DIAGNOSTIC PROCEDURE FOR NO-DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK FWD SWITCH.
2 CHECK FWD INDICATOR LIGHT.
1)Turn the ignition switch to OFF.
2)Remove the combination meter.
3)Remove the FWD indicator light bulb from
combination meter.
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND FWD SWITCH.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from TCM and
FWD switch.
3)Measure the resistance of harness between
TCM and FWD switch connector.
Connector & terminal
(B55) No. 20 — (F67) No. 30:
4 CHECK HARNESS CONNECTOR BETWEEN
FWD SWITCH AND CHASSIS GROUND.
Measure the resistance of harness between
FWD switch and chassis ground.
Connector & terminal
(F67) No. 29 — Chassis ground:
5 CHECK HARNESS CONNECTOR BETWEEN
TCM AND FWD SWITCH.
Measure the resistance of harness connector
between TCM and body to make sure that cir-
cuit does not short.
Connector & terminal
(B55) No. 20 — Chassis ground:
6 CHECK INPUT SIGNAL FOR TCM.
1)Turn the ignition switch to OFF.
2)Connect the connector to TCM and FWD
switch.
3)Turn the ignition switch to ON.
4)Measure the signal voltage for TCM while
installing the fuse to FWD switch connector.
Connector & terminal
(B55) No. 20 (+) — Chassis ground ( − − − − ):
7 CHECK INPUT SIGNAL FOR TCM.
Measure the signal voltage for TCM while
removing the fuse from FWD switch connector.
Connector & terminal
(B55) No. 20 (+) — Chassis ground ( − − − − ):
8 CHECK HARNESS CONNECTOR BETWEEN
TCM AND COMBINATION METER.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from TCM and
combination meter.
3)Measure the resistance of harness between
TCM and diagnosis connector.
Connector & terminal
(B56) No. 2 — (i11) No. 4:
AUTOMATIC TRANSMISSION (DIAGNOSTICS)
Check
When the fuse is inserted to
FWD switch, does LED light
up?
Is the FWD indicator light bulb
OK?
Is the resistance less than 1
Ω?
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
Is the voltage less than 1 V in
FWD switch while installing?
Is the voltage between 6 and
9.1 V in FWD switch while
removing?
Is the resistance less than 1
Ω?
AT-109
Yes
Go to step CHECK Go to step 2.
BRAKE
SWITCH.<Ref. to
AT-110, CHECK
BRAKE SWITCH.,
Diagnostic Proce-
dure for No-diag-
nostic Trouble
Code (DTC).>
Go to step 3. Replace the FWD
indicator light bulb.
<Ref. to IDI-15,
Combination
Meter Assembly.>
Go to step 4. Repair the open
circuit in harness
between TCM and
FWD switch con-
nector.
Go to step 5. Repair the open
circuit in harness
between FWD
switch connector
and chassis
ground.
Go to step 6. Repair the short
circuit in harness
between TCM and
FWD switch con-
nector.
Go to step 7. Go to step 11.
Go to step 8. Replace the TCM.
<Ref. to AT-46,
Transmission Con-
trol Module
(TCM).>
Go to step 9. Repair the open
circuit in harness
between TCM and
combination meter
and poor contact
in coupling con-
nector.
No